Circuit breaking device for electrical alarm installations



Aug. 29, 1939.- c. ROTH 2,171,245

CIRCUIT BREAKING DEVICE FOR ELECTRICAL ALARM INSTALLATIONS Filed Aug. 3,1937 Profecf/ye Ens 0029 a l 1 7 0 0 dz 7 29. j

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Patented Aug. 29, 1939 UNITED STATES PATENT OFFICE Christian Roth,Zurich, Switzerland Application August 3, 1937, Serial No. 157,121 InSwitzerland August 10, 1936 9 Claims.

An application has been filed in Switzerland on August 10, 1936.

This invention relates to a circuit breaking device for electrical alarminstallations which operate with closed circuit.

For protecting doors, pendulum circuit breaking devices have alreadybeen proposed, which include a lever system stationarily carried withrespect to the door to be protected, which lever system contacts at oneend under pressure against the door and with its other end effects thecontrol of the alarm contacts. Experience has shown, however, that thesependulum circuit breaking devices are very diflicult to adjust and oftengive rise to false alarms. Moreover, they are expensive to obtain andalso to fit.

The novel circuit breaking device according to this invention differsfrom the above in that a contact casing, arranged in a carrier andfreely swingable in two planes perpendicular to one another, is providedwith a contact member standing under variable spring pressure and isinserted in the closed circuit, which contact member is electricallyconnected in the vertical position of the casing with the latter througha ball, which ball interrupts the circuit as soon as the casing isdisplaced from the vertical position.

In order that the invention may be fully understood I will now describeone embodiment thereof by reference to the accompanying drawing, in

which:

Fig. 1 is a vertical section of a circuit breaking device constructedaccording to the invention.

Fig. 2 is a front elevation of a carrier without the contact casing, and

Fig. 3 is a section on the line III-III of Fig. 1.

The circuit breaking device consists of a metallic cylindricalcontact-forming casing 4 closed by a cover piece 5, in which is arrangedand axially displaceable connecting member 8 having a radial bore 1. Theconnecting member 5 lies inside an insulating sleeve 8 and rests on aninsulating disc 9, which itself lies on a regulating disc it. Theregulating disc It is formed with an external thread so as to beadjustably insertible in the lower portion of the casing 4.

The connecting member 6 carries on a spring [I a second connectingmember 52 arranged within the insulating sleeve 8 and having a contactpin it. On the connecting member 1?. is arranged an insulating disc N,which serves as a support for a spring disc it or the like, which isinsulated from the casing i by means of an in" sulating disc it.

In the upper part of the casing 4 is a chamber (Cl. ZOO-54) I! in whichis inserted a ball i8, which lies on an intermediate wall sloping fromall sides towards the axis of the casing. At the axis of the casing thesaid wall is formed with a hole for the reception of the contact pin 3,which is pressed, in 5 the vertical position of the casing 4, up againstthe ball 58, so as to produce an electrical connection between theconnecting member 6 and the casing 4. By means of the regulating disc I0,

it is possible to adjust the pressure of the pin l3 10 on the ball |8 toany desired extent, so that even small disturbances acting on thecircuit-breaking device, with the position of the casing 4 remainingvertical, cause a current interruption. This current interruption isassured in that the disl5 turbances are communicated to the connectingmember l2, which in consequence of the slight spring pressure, is set inoscillation, which can only be stopped by compressing the spring II, andwhich lead to the breaking of the connection 20 between the ball I 8 andthe contact pin l3 even if of a momentary nature only.

To the cover 5 of the casing is secured a metallic bolt l9, which ispivoted to a rotatable shaft 2| horizontally mounted in a carrier 20,consist- 25 ing of insulating material, by means of a screw 22 or thelike, so that the casing 4 can swing to both sides out of the verticalposition in a vertical plane through the axis of the shaft 2|. This ispossible in that the bolt l9 passes through an 30 elongated hole 23 inthe shaft 2|. In one end of shaft 2| is secured a screw 24 which, on theone hand, clamps a cable eye or socket 25, and, on the other hand, atube 26 inserted in a bore of the shaft 2 35 Above the shaft 2| isarranged, parallel to the said shaft, an axially displaceable shaft 21having a disc 28 at one end thereof. This shaft 2'! forms a carrier foran adjustable gauge pin 29 having a nut 30 and a lock nut 3|. The nut3|] 40 serves as a stop for the compression spring 32, which tends tomove the shaft 21 with the gauge pin 29 out of the carrier 20.

A second cable eye or socket 33 is secured in the carrier 20, whichsocket is connected on the 45 one hand by means of a cable, not shown inthe drawing, to one pole of a source of current, and on the other handby means of a cable 34 to the connecting member, 6, the latter beingclamped in position by means of a clamping screw 35. 50 The cable eye 33is thus in electrical connection with the cable eye 25 through cable 34,the connecting member 6, the connecting member l2, the ball I 8, thecasing 4, the bolt l9 and the shaft 2|. The cable eye 25 is itselfconnected, to com- 55 plete the closed circuit, with the second pole ofthe source of current, by means of a cable 39 through the medium of arelay not shown.

The method of operation of this circuit breaking device is as follows:The carrier 20 is secured to a door 35, window or other suitable part,in such a manner that the head 31 of the gauge pin 29 lies on thestationary frame 38. The adjustability of this gauge pin enables thedevice to be easily adjusted in accordance with the thicknesses, etc. ofthe doors. In the fitted position the disc 28 lies adjacent the free endof the bolt l9. On any attempt to open the door without causing anydisturbances, the gauge pin 29, owing to the pressure of the spring 32,remains constantly in engagement with the frame 38 and the disc 28presses the bolt l9 and thus the contact casing 4 out of the verticalposition, the ball l8 being thereby shifted out from its seat on thecontact pin 53 and interrupting the flow of current.

' The improved device can, however, also be used where it is suitablealso to employ tensioning wires Sea, such as are known for protectingdoor panels, walls, roofs, floors and the like. The tensioning wire issecured at the free end of the tube 26, so that the latter can turn theshaft 2| in either direction of rotation. The other end of the wire issecured at any suitable place. By the arrangement of guide rollers, notshown, thei'wire' can'change its direction as desired. Even relativelysmall forces acting on the tension wire cause, as experiments haveshown, the turning of the shaft 2| and thus a swinging of the contactcasing 4 out ofits vertical position so as to interrupt the current.

Further trials have shown that the circuitbreaking device functionsperfectly satisfactorily without the use of tension wires, forprotecting windows, doors and the like, in that the cutting out ofwindow panes or door panels will produce disturbances or vibrations,which are sufficient to set the connecting member 52 in the contactcasing in oscillation, thereby breaking the circuit.

The improved circuit breaking device is not only suitable to replaceknown considerably more expensive apparatus without its effectivenessbeing in any way inferior to these known arrangements; but it enables,owing to the small initial costs, places to be protected which wouldotherwies remain unprotected on account of the disadvantages inherent inthe known constructions. i 7

I claim: r

1. In a circuit-breaking device for electrical alarm installationsoperating with normally closed circuit, the provision as one contactdevice in said circuit, of an insulated sleeve; a pair of connectingmembers for connection to one pole of a source of current carried insaid sleeve; a'spring interposed between said mem bers adapted to retainsaid members in spaced relation one at each end of said sleeve; acontact pin on said other member said pin protruding from said sleeveand being electrically con-- nected'to said first mentioned memberthrough said spring; and current conducting means for connection to theother pole of said current source, said means being disposed adjacentand in engagement with said pin and the dimensions of said spring beingsuch that external vibrations transmitted to said casing cause saidspring to oscillate and said pin to become temporarily disengaged fromsaid current conducting means.

2. A circuit-breaking device for electrical alarm installationsoperating with normally closed circuit, comprising the sum-combinationof: a swingable casing for electrical connection to one pole of acurrent source; a platform carried in said casing, said platform havinga central perforation therein and sloping on all sides towards saidperforation; a movable ball resting on said platform and in electricalconnection with said. casing; and means, in said casing connecting saidball, in normal rest position of said casing, with the other pole ofsaid source of current, whereby on displacement of said casing from itsnormal position, said ball becomes disengaged from said connecting meansthereby breaking the circuit therethrough and on return of said casingto normal rest position, said circuit is automatically remade throughsaid ball.

3. A circuit-breaking device for electrical alarm installationsoperating with normally closed circuit, comprising the sub-combinationof: a swingable casing for electrical connection to one pole of a sourceof current; a spring-urged pin electrically connected to the other poleof said source of current, and said pin being insulatedly carried insaid casing; a movable ball made of current conducting material in saidcasing; and means for automatically contacting said ball with said pinwhen said casing is in the normal position of rest to connect said pinto said casing and close the circuit, the arrangement being such that,on displacement of said casing out of the rest position, said ball isdisengaged from said contact member and thereby breaks the circuit toactuate the alarm and on return of said casing to rest position, saidcircuit is automatically remade.

4. A circuit-breaking device for electrical alarm installationsoperating with normally closed circuit comprising the subcombination of:a swingable casing for electrical connection to one pole of a source ofcurrent; a spring-urged pin carried in, but insulated from, said casingfor electrical connection to the other pole of said source of current; acentrally perforated platform mounted in said casing above andconcentrically with the axis of said pin, said platform sloping on allsides toward said perforation; an electrically conducting ball restingon said platform so as normally to contact said pin and complete thecircuit through said pin and casing, whereby on displacement of saidcasing from the normal rest position thereof said ball becomesdisengaged from said contact pin thereby breaking the circuittherethrough and sounding the alarm and on return of said casing to restposition, said circuit is automatically remade through said ball.

5. A circuit-breaking device for electrical alarm installations for adoor, window and the like, operating with normally closed circuit,comprising the sub-combination oi: a carrier member; a swingable casing,for connection to one pole of a source of current, carried by saidcarrier; a contact pin for connection to the other pole of said sourceinsulatedly mounted in said casing; a slidable spindle carried on andprojecting from said carrier member; a spring on said spindle urgingsaid spindle outwardly, said spindle being normally held by said door insaid carrier member against the action of said spring; a movable ball insaid casing normally engaging said pin and said casing to complete thecircuit therethrough, whereby on movement of said casing out of itsnormal position, said circuit is broken, and means for automaticallyreturning said ball to normal pin-engaging position when said casingreturns to its normal rest position.

6. A circuit-breaking device for electrical alarm installationsoperating with normally closed circuit, comprising the sub-combinationof: a swingable casing for electrical connection to one pole of a sourceof current; an intermediate current conducting means housed in andengaging with said casing; a contact pin insulatedly carried in saidcasing; a spring for electrical connection to the other pole of saidcurrent source directly engaging said contact pin, said spring normallyurging same into engagement with said conducting means when said casingis in its normal posiion and spring being so dimensioned that externalvibrations transmitted to said casing cause said spring to oscillate andsaid contact pin to become temporarily disengaged from said intermediatecurrent conducting means.

7. A circuit-breaking device for electrical alarm installationsoperating with normally closed circuit, comprising the sub-combinationof: a carrier member; a rotatable shaft for connection to one pole of asource of current mounted in said carrier member; means for rotatingsaid shaft; a casing carried by and in electrical connection with saidshaft in a normally vertically depending position; a spring-urged pinfor electrical connection to the other pole of said current sourceinsulatedly carried by said casing; a movable ball made of currentconducting material in said casing; and means for automaticallycontacting said ball with said pin when said casing is in the normalposition of rest to connect said pin to said casing and close thecircuit, the arrangement being such that, on displacement of said casingout of the rest position, said ball is disengaged from said contactmember and thereby breaks the circuit to actuate the alarm and on returnof said casing to rest position, said circuit is automatically remade.

8. A circuit-breaking device for electrical alarm installations forindicating the movement of an object such as a door and operating withnormally closed circuit, comprising the sub-combination of: a carriermember; a rotatable shaft for connection to one pole of a source ofcurrent, mounted in said carrier member; said shaft having a slottherein; a depending bolt swingably carried by and electricallyconnected to said shaft and passing through said slot; a normallyvertical casing carried by and in electrical connection with said bolt;a displaceable spindle normally held in said carrier member by contactwith said door; a spring on said spindle adapted to urge said spindleoutwardly from said carrier member on the movement of said door in anopening direction, to engage said bolt and swing said casing; a contactmember for connection to the other pole of said current sourceinsulatedly carried by said casing, and displaceable means in saidcasing adapted normally electrically to connect said contact member andsaid casing to close the circuit therethrough and, on the swinging ofsaid casing out of its normal position, to break said circuit.

9. A circuit-breaking device for electrical alarm installationsoperating with normally closed. circuit, comprising the sub-combinationof: a carrier member; a rotatable shaft for electrical connection to onepole of a source of current mounted in said carrier member; a dependingtubular member carried by said shaft, said member having a hole thereinfor connecting to one end of a tension wire, the other end of which isconnected to an external stationary object; a casing carried by andelectrically connected to said shaft in a normally vertically dependingposition; a contact member for connection to the other pole of saidsource of current insulatedly carried by said casing; current conductingmeans in said casing, said means being normally so disposed as toconnect electrically said casing and said contact member and complete acircuit therethrough; the arrangement being such that, on displacementof said casing from said vertical position, on swinging of said tubularmember by displacement of said tensioning wire, said current conductingmeans is automatically displaced and said circuit is broken.

CHRISTIAN ROTH,

